22nd September

Threat to premier west coast shellfish ground

& Gery Flynn

All-inclusive participation required for management of Clew Bay. Photo Shay FennellyAll-inclusive participation required for management of Clew Bay. Photo Shay Fennelly

Shellfish producers in Clew Bay have told Inshore Ireland they are extremely concerned over proposals by Mayo County Council to discharge leachate from its Derrinumera landfill into Newport Bay.

“The proposed discharge point is less than half a mile from several native oyster beds in the estuary of one of the country’s finest salmon rivers, the Burrishoole,” Alan Stoney, secretary of the Clew Bay Oyster Co-operative said.

According to Stoney, the intended mechanism to render the effluent ‘safe’ is to dilute it sufficiently with the water in Clew Bay.


“It would appear that Mayo County Council has not taken fully into account the possible long-term impact that this would have on the delicate marine ecosystem that exists.

“Most of the organisms, especially shellfish, are ‘bio accumulators’, i.e. they filter large volumes of water, removing material dissolved or suspended in the water. Then they lay this material down in their tissue as they grow.”

Since 1979, the Clew Bay Oyster Co-operative has produced thousands of tonnes of premium product. “This product is sought worldwide by consumers who rely on the knowledge that the fish they are eating is of the highest quality. This quality ultimately depends on one thing alone, the cleanliness of the water in Clew Bay.”

Stoney added that the effect in terms of habitat deterioration and loss of confidence in produce was hard to predict. “But I believe it would resonate far from the source of contamination,” he said.

Common concerns
Other bay users echo these sentiments and have voiced their concerns to Mayo County Council under the umbrella of the Clew Bay Marine Forum (CBMF).

In a letter to Mayo County Council dated July 5 2004, clarification was sought on a number of issues:

What assurance could be given that discharge from the proposed site into a ‘food production area’ would be 100% safe, 100% of the time.

What was the proposed level of treatment of both landfill leachate and sludge hub centre leachate

Has an independent assessment taken place as to the long-term effects of leachate discharge on the Castlebar River

What wastewater treatment standards will be applied prior to dilution

Will UV treatment be considered for the Newport WWTP and also for the site at Derrinumera

Two Environmental Impact Statements due in November 2004 are still awaited.

Free low into bay
Michael Mulloy, Chairman of the CBMF and a director of Blackshell Farm Ltd, which produces rope-grown mussels in Clew Bay, told Inshore Ireland of his concerns.

He fears for the future viability of a company that began farming mussels there in 1983. “The proposed discharge point at Rosmore is less than three miles from where we harvest five hundred tonnes of mussels annually.

“Mayo County Council has been unable to give us the assurances we require. I believe this is because they don’t know what actually went into the dump over the last twenty years, and have no idea either what is likely to go into it in the future.”

Mulloy argues that the precaution taken by Mayo County Council to install sealed rubber cells on land to contain the leachate and to prevent it from contaminating the groundwater is in stark contrast to how they propose dealing with it once it has been pumped offshore:

“They seem to have gone to great bother to create a closed system for the leachate on land; but when it comes to Clew Bay the plan is simply to open the valves and let this poison flow into the sea. In my view this an out-of-sight-out-of-mind solution.”

Mulloy contends that the proposal puts the whole notion of designation into context: “Is Clew Bay a designated area or not? If it is, how does that influence the type of stuff that can be flushed into it?

Liam Doherty, marine manager of Clare Island Seafarm Ltd, which produces two thousand tonnes of farmed salmon from its four sites in Clew Bay, has similar concerns:

“The company has been farming salmon in Clew Bay since 1984. The main growing site is just off Clare Island but we have two other sites in the inner bay just two miles from the proposed discharge point.

“One of these sites is where fish are kept prior to harvesting. The salmon are moved to this site in December for harvesting in rough weather. We are very concerned because we farm organically, and if leachate is pumped into the bay, this could wreck our business over night. That kind of stuff shouldn’t be coming into this bay at all.”

Inshore Ireland invited Mayo County Council to respond but at the time of going to press, no comment had been received. The Northwest Regional Fisheries Board was also asked to confirm that adequate research has been conducted to show that the proposed works would not affect the native oyster beds and that water quality would be maintained. No reply was received. The Environmental Protection Agency told Inshore Ireland that to date it had not received an EIS for the proposed works at Derrinumera.

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